The group said in an unscheduled update that its January statement claiming it was on track to deliver profits in line with market expectations is “no longer valid”.
It warned that trading headwinds, efforts to put the firm on a secure financial footing and macroeconomic uncertainties were hitting the company hard.
Shares were down 12% at 2.8p in morning trade.
In February, Debenhams secured a £40 million lifeline from its lenders to act as a bridge while the company continues talks for a longer-term refinancing.
“Discussions with stakeholders have now progressed to include options to restructure our balance sheet in order to address our future funding requirements, and are continuing constructively,” it said on Tuesday.
Debenhams also plans to shut 50 stores amid long-term pressures on the high street, putting 4,000 jobs at risk.
Boss Sergio Bucher said on Tuesday: “We are making good progress with our stakeholder discussions to put the business on a firm footing for the future. We still expect that this process will lead to around 50 stores closing in the medium term.
“Our priority is to secure the best outcome for the business and all our stakeholders, whilst minimising the number of store closures and job losses. To do this, as we have said before, we will need the support of both landlords and local authorities to address our rents, rates and lease commitments.”
Debenhams also said that in the eight weeks since January 10, sales have improved somewhat, but are still in decline.
Gross transaction value fell 5% in the period, with like-for-like sales down 4.6%.
Overall, for the 26 weeks to March 2 comparable sales are down 5.3%. The UK was down 6% with international down 2.3%.
Debenhams said that an £80 million cost-saving programme is on track.
The group is also being stalked by Sports Direct boss and shareholder Mike Ashley, who has said the firm has little chance of survival